The present invention relates to an apparatus and method for protecting at least one component, especially an optical component, of a light source.
Sources of light beams, and in particular laser systems, are used for ablating biological and non-biological substrates and for cutting various materials. In such applications, energy, especially laser energy, is applied to heat the substrate or material, or some component thereof, causing controlled vaporization. In the case of lasers, the systems thereof generally include a light source for generating laser light, and optical components for directing the laser beam to a target. The laser source may produce continuous or pulsed laser energy output. The delivery of laser energy to a target specimen and subsequent vaporization of a portion of the specimen often produces byproducts, such as smoke, carbonized particles and/or splattered particles from the specimen. These byproducts pose a threat to the consistent operation of the laser system in that they may be deposited upon the objective optics of the system, thus damaging or altering the optical components, reducing output power, distorting the pattern of energy distribution within the light or laser beam, or otherwise contributing to the degradation of the system.
One particular application of such laser systems includes laser finger perforators that are used to sample capillary blood for analysis of glucose and other blood chemistry measurement. The laser penetrates the finger by vaporizing and ablating tissue to create a small hole in the skin down to and including intersecting some of the capillaries. The vapor and additional small particles that are ablated when creating the hole in the finger can adhere to the surface of the laser lens. As described above, such adhered material will change the characteristics of the lens, such as its focus and light transmission parameters. These resultant changes can cause pain to the patient and/or make it more difficult to draw blood.
In view of the foregoing, it can be seen that there is a great need for providing means to protect the components of a light source, and in particular the optics thereof. This has been addressed by the prior art in several ways. One such way is to position the optics at a distance from a specimen that is great enough that vaporized or ablated material from the target area cannot reach the optics. Such a passive approach makes for a rather large device and is not a satisfactory solution. U.S. Pat. No. 5,148,446, Radich, discloses the protection of the objective lens of a laser system by directing a flowing fluid, such as air, over and away from the surface of the lens, thus directing ejected particulates away from such lens. This system is complicated and expensive, generally requires external power supply and pumps, and is not amenable to miniaturization. Also known are disposable protective devices that are manually inserted between the objective optics of laser system and the source of possible ablated material. Such protective devices are single-use components that must be discarded and replaced for each procedure (see PCT publications WO 98/04201 and WO 98/47435).
It is therefore an object of the present invention to provide an improved means for protecting components of a light source, and in particular an apparatus and method that can be used for extended procedures and/or for multiple procedures, thereby reducing the amount of waste generated, the number of disposable components that need to be provided, the danger of forgetting to replace a used protective device, and possibly also reducing the cost of operation of such a system.